Desalination: the State of the Art

Desalination technology is applied in many areas of the world to provide fresh water from brackish or seawater sources. The paper reviews the technology which is available and discusses both distillation and membrane processes. Indications of capital and operating costs are provided.     

Design and Construction of the Isle of Dogs Pumping Station

T he pumping station employs submersible pumps to drain surface water from the newly developed Enterprise Zone of the Isle of Dogs, London, and discharges storm overflows from an existing combined sewer system. At full development the nominal capacity of the pumps will be 12 m³/s.
After screening the flow passes to the pump chamber, where 12 main and two sump pumps are located. The main pumps deliver through individual syphon discharge pipes to a high level surge tank, which drains by gravity through a short outfall to the river Thames.
Diaphragm walling was used in the construction of the foundations and underground work. Attractive brick buildings form the pump hall and building housing the high voltage electrical equipment and the transformers. Steel sheet piles protect the river frontage.
The station will operate unattended, and will be controlled automatically by water level sensors. Supervision will be by telemetry links to the Thames Water Authority's (TWA) area control centre at Abbey Mills.     

The Flood-Prevention Scheme of Venice: Experimental Module

Records exist of the flooding of Venice from the days of the Republic. During the last century flooding incidents have become more severe due to subsidence of the city and rising water levels in the Adriatic. Calamitous flooding occurred in 1966, and two devastating floods were experienced during the last decade. The 'Special Law for Venice', enacted by the Italian Parliament in 1973, paved the way for a competition to devise a flood-prevention scheme.
A consortium of Italian contractors, who were commissioned to submit proposals for the implementation of the scheme, designated Technital Spa of Verona to carry out the design of the flood-prevention works and improvements within the lagoon. This resulted in the design of three movable barrages to seal off the Venice lagoon in the event of a flood. The construction of a full-size gate and caisson (the prototype of the eighty gates forming the barrages) was subsequently authorized.
This paper describes the experimental module containing the buoyant gate and its caisson, its novel features as well as some of the events leading up to its design and construction.     

Basic windpower

Two examples are given, in which by self-help, whole communities have spontaneously adopted simple forms of small-scale windpower using local materials. This has enabled them to increase their well-being. The first example refers to parts of the United States and was put on record by the University of Nebraska. The second refers to the sail-mills of Eastern Crete and is based on field and laboratory work carried out by the author.     

3. Design and Construct Contracts in the Water Industry - The Way Ahead? The Consultant's Viewpoint

Stages in developing engineering projects within the water industry are reviewed, with particular reference to the construction of wastewater treatment plants by adopting a design and construct approach. This is compared with the involvement of consulting engineers and the more traditional practices. The effect on responsibilities and the influence of the approaches to the management, engineering and outcome of the project are considered.     

Ambient energy in the UK

This paper reviews the position of the renewable energy resources in the UK in 1986. Their historical development is traced and the record of UK Government support for renewable Research and Development is compared with that of some other western industrial countries. Several resources show considerable promise and are already economically attractive. Each of the renewable possibilities is examined in detail in the paper, a number of socio-economic issues are also raised.